When manually feeding a workpiece toward a rotating circular saw blade or cutting tool as in a table saw or jointer, thickness or shaper plane or when ripping the workpiece on a radial arm saw a kickback of the workpiece by the rotating tool or blade occasionally occurs creating a hazard. Kickbacks may occur for various reasons but most frequently result from a binding of the workpiece between the rotating blade and fence or pinching of the cutting tool in the kerf of the workpiece.
Heretofore anti-kickback devices have conventionally comprised some form of gravity actuated or spring pressed, pivoted pawls arranged to slide over the surface of a workpiece when moved in a feeding direction or when the cutting blade is moved through the workpiece in a feeding direction and to dig into the surface of the workpiece to stop kickback movement of the workpiece in a reverse direction toward the operator. Usually these pawls are provided with one or more relatively sharp teeth in contact with the surface of the workpiece and which in instances causes objectionable marring of the surface. Moreover, the pressure of these spring pressed pawls on the upper surface of a workpiece resting on a worktable varied with the thickness of the workpiece were ineffective when making bevel cuts and were also ineffective to prevent kickbacks of workpieces having hard, smooth surfaces because of their failure to dig in to such surfaces.